Im growing out 13 Toxotes blythii in a 75 gallon, i know its kind of crowded but they all stick with each other anyway. Just deciding on what size tank im upgrading too in September.
I love these things, one day I will do a tank with a bug canopy to watch them shoot!-)
That's what you should do....
180g with a 6*2 plastic vivarium on top, cut the bottom out and create an overhanging rainforest biotope with a waterfall.